[PATCH v7 8/9] drm: writeback: clean up writeback connectors in drm_connector_cleanup()

[Dmitry Baryshkov]

Only drmm_writeback_connector_init() registers
drm_writeback_connector_cleanup(). Connectors set up with
drm_writeback_connector_init() (amdgpu, komeda, malidp, rcar-du, vc4)
never drop the formats blob or free the jobs still on the queue, leaking
them together with their framebuffer and fence references.

Call drm_writeback_connector_cleanup() from drm_connector_cleanup() for
writeback connectors, the same way the HDMI audio and SCDC state is torn
down there, so it runs for both kinds of initialization. The drmm action
now just wraps it. Clearing the blob pointer makes the second invocation
a no-op and also covers drm_connector_cleanup() being called after a
failed __drm_writeback_connector_init().

Fixes: 935774cd71fe ("drm: Add writeback connector type")
Assisted-by: LLM
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/drm_connector.c     |  3 +++
 drivers/gpu/drm/drm_crtc_internal.h |  3 +++
 drivers/gpu/drm/drm_writeback.c     | 30 +++++++++++++++++++++++-------
 3 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 893716a9e489..1c2bef5e0636 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -929,6 +929,9 @@ void drm_connector_cleanup(struct drm_connector *connector)
 	if (connector->hdmi.scdc_work_initialized)
 		cancel_delayed_work_sync(&connector->hdmi.scdc_work);
 
+	if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
+		drm_writeback_connector_cleanup(connector);
+
 	platform_device_unregister(connector->hdmi_audio.codec_pdev);
 
 	if (connector->privacy_screen) {
diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
index 3492787c3697..f60216adcd31 100644
--- a/drivers/gpu/drm/drm_crtc_internal.h
+++ b/drivers/gpu/drm/drm_crtc_internal.h
@@ -329,4 +329,7 @@ static inline void drm_panic_unregister(struct drm_device *dev) {}
 static inline void drm_panic_init(void) {}
 #endif
 
+/* drm_writeback.c */
+void drm_writeback_connector_cleanup(struct drm_connector *connector);
+
 #endif /* __DRM_CRTC_INTERNAL_H__ */
diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
index 2f6a7b50336c..272012a70efe 100644
--- a/drivers/gpu/drm/drm_writeback.c
+++ b/drivers/gpu/drm/drm_writeback.c
@@ -21,6 +21,8 @@
 #include <drm/drm_property.h>
 #include <drm/drm_writeback.h>
 
+#include "drm_crtc_internal.h"
+
 /**
  * DOC: overview
  *
@@ -271,21 +273,27 @@ EXPORT_SYMBOL(drm_writeback_connector_init);
 
 /**
  * drm_writeback_connector_cleanup - Cleanup the writeback connector
- * @dev: DRM device
- * @data: Pointer to the writeback connector to clean up
+ * @connector: Writeback connector to clean up
  *
  * This will decrement the reference counter of blobs. It will also clean the
  * remaining jobs in this writeback connector. Caution: This helper will not
  * clean up the attached encoder and the drm_connector.
+ *
+ * Called from drm_connector_cleanup() for all writeback connectors.
  */
-static void drm_writeback_connector_cleanup(struct drm_device *dev,
-					    void *data)
+void drm_writeback_connector_cleanup(struct drm_connector *connector)
 {
-	unsigned long flags;
+	struct drm_writeback_connector *wb_connector =
+		drm_connector_to_writeback(connector);
 	struct drm_writeback_job *pos, *n;
-	struct drm_writeback_connector *wb_connector = data;
+	unsigned long flags;
+
+	/* __drm_writeback_connector_init() has failed */
+	if (!wb_connector->pixel_formats_blob_ptr)
+		return;
 
 	drm_property_blob_put(wb_connector->pixel_formats_blob_ptr);
+	wb_connector->pixel_formats_blob_ptr = NULL;
 
 	spin_lock_irqsave(&wb_connector->job_lock, flags);
 	list_for_each_entry_safe(pos, n, &wb_connector->job_queue, list_entry) {
@@ -295,6 +303,14 @@ static void drm_writeback_connector_cleanup(struct drm_device *dev,
 	spin_unlock_irqrestore(&wb_connector->job_lock, flags);
 }
 
+static void drm_writeback_connector_cleanup_action(struct drm_device *dev,
+						   void *data)
+{
+	struct drm_writeback_connector *wb_connector = data;
+
+	drm_writeback_connector_cleanup(&wb_connector->base);
+}
+
 /**
  * drmm_writeback_connector_init - Initialize a writeback connector
  *
@@ -333,7 +349,7 @@ int drmm_writeback_connector_init(struct drm_device *dev,
 	if (ret)
 		return ret;
 
-	ret = drmm_add_action_or_reset(dev, drm_writeback_connector_cleanup,
+	ret = drmm_add_action_or_reset(dev, drm_writeback_connector_cleanup_action,
 				       wb_connector);
 	if (ret)
 		return ret;

-- 
2.47.3